1. Field of the Invention
The present invention relates to a display and a fabricating method thereof, and more particularly to an active organic electroluminescence panel display and a fabricating method thereof.
2. Description of the Related Art
Because of the shrinkage of semiconductor device and displays, portable devices are now available to consumers. As to displays, cathode ray tubes (CRT) dominate the market because of its high image quality and low cost. However, because of space restriction, power consumption and environmental concern, CRT still has some issues that need to be resolved. Therefore, thin film transistor liquid crystal display, which offers high image quality, small space occupation, low power consumption and radiation free, has gradually replaced CRT.
Flat panel displays include liquid crystal display (LCD), organic electroluminescence display (OELD) and plasma display panel (PDP), etc. OELD, a dots matrix type display having emissive devices, has high brightness, high efficiency, low weight, high effective contrast ratio and low power driving. The power consumption of OELD is less than those of CRT, PDP and LCD. Moreover, because its performance is independent of red, green and blue lights, OELD is now deemed as the main trend for the next generation of flat panel displays.
OELD includes active and passive drive displays depending on the driving modes. The service life and efficiency of the passive drive display will decay depending on the size and resolution thereof. The active drive OELD has gradually replaced the passive type to date.
The active drive OELD includes thin film transistors (TFT) for driving the voltage required thereby. Generally, the process of fabricating the TFT can be varied depending on a position of an indium tin oxide (ITO) anode layer, e.g. on the top or the bottom of the source/drain terminals (ITO on Top and ITO on Bottom, respectively). The process also depends on the material used, such as polysilicon or amorphous silicon, which is applied in the silicon layer. Referring to FIG. 1, during the process of fabricating the polysilicon TFT substrate, the ITO is positioned on Top of the source/drain terminals, a contact opening 114 is formed within the passivation layer 106 on the dielectric layer 102 and the source/drain 104. The ITO anode layer 108 is filled into the contact opening 114 for electrically connecting to the source/drain 104. A red, green and blue light organic luminescent layer 110 is configured on the ITO anode layer 108 and the passivation layer 106. The cathode layer 112 is configured on the organic luminescent layer 110. Because of the large step height of the surface of the ITO anode layer 108 and the passivation layer 106, particularly at the place marked A corresponding to the contact opening 114, and at the place marked B corresponding to the edge of the source/drain 104, the thickness of the organic luminescent layer 110 thereof will be reduced and the cathode layer 112 easily contacts with the anode layer 108 resulting in shorting.
Additionally, in the conventional method of forming the organic luminescent layer 110, the shadow mask directly contacts the anode layer and the passivation layer and the organic luminescent layer are formed thereon by sputtering. The shadow mask is then removed to repeat the sputtering process for several times to form the red, green and blue organic luminescent layers on the anode layer and the passivation layer, respectively. During the sputtering processes, because the shadow mask is repeatedly made to come in contact to and then separated from the TFT substrate, damage will result therefrom adversely affecting the performance of the device.